Flap slitter and positioner



March 19, 1968 B. .1. NIGRELLI ETAL 3,373,543

FLAP SLITTER AND POSITIONER 3 Sheets-Sheet 1 Filed Aug. 9, 1965 March 1968 B. J. NlGRELLl ETAL 3,373,543

FLAP SLITTER AND POSITIONER Filed Aug. 9, 1965 3 Sheets-Sheet 2 t java-7122715:

March 19, 1968 J. NIGRELLI ETAL 3,373,543

FLAP SLITTER AND POSITIONER 3 Sheets-Sheet 3 Filed Aug. 9, 1965 United States Patent() 3,373,543 FLAP SLITTER AND POSITIONER lliagio .l. Nigrelli, Northbrook, and Wendell E. Standley, Lake Forest, Ill., assignors to Johns-Nigrelli-Johns, Inc, Slrokie, Ill., a corporation of Illinois Filed Aug. 9, 1965, Ser. No. 478,371 Claims. (Cl. 53381) ABSTRACT OF THE DISCLOSURE The mechanism herein disclosed is employed to sever the connections between the edges of joined, downturned closure flaps held along the outer surfaces of the vertical Walls of a filled paperboard container as the container is advanced along a given path. Severing means, located in the path of the strips, break or cut such strips as the container is propelled past such severing means. The released flaps are then swung to closed position.

The present invention relates to slitting devices for releasing joined container flaps which are connected to stay in down folded condition at the outsides of paperboard containers while the containers are being filled.

In certain container filling operations it is desirable to retain the top closure flaps close to the sides and ends of the paperboard containers instead of allowing them to extend outwardly as would normally 'be the case if the flaps were not retained. One expedient that is employed is to make up the container blank to leave short, integral holding strips at opposite corners of the container when the container is connected in tubular form. These holding strips join a side wall cover flap and an end wall cover flap at opposite corners of the container. Thus, by first folding the two pairs of joined cover flaps against their attached carrying walls while the container is in flat tubular condition and then expanding the container to open tubular form, the cover flaps will be retained in close relation to their respective side and end Walls. The bottom closure flaps will be secured in the usual manner, thus preparing the container to receive its contents, such as bottles.

After the containers are filled the strips connecting the cover flaps are severed and the container may then be closed in a usual manner.

The primary object of the invention is to provide improved mechanical means for breaking or severing the strips connecting the cover flaps.

A more specific object is to provide conveying means along which a filled container, with flaps held down, may be advanced so as to bring first one set of connected cover flaps and then the other set against strip severing means such as cutting blades to release the flaps one from the other.

A further object of the invention is to initiate the folding of the severed flaps so that they may be readily brought to outwardly or upstanding positions preparatory to further closing operations.

Additional and more specific objects and advantages of the present invention will become apparent as the description proceeds.

In the drawings FIGURE 1 is a side elevation taken partly in section along line 1-1 of FIGURE 2;

FIGURE 2 is a top plan view of the device;

FIGURE 3 is a vertical cross-sectional view, taken along line 33 of FIGURE 1 looking in the direction of the arrows;

FIGURE 4 is a vertical sectional view taken along line 44 of FIGURE 2 looking in the direction of the arrows; and

3,373,543 Patented Mar. 19, 1968 FIGURE 5 is a perspective view of a paperboard container showing how the cover flaps are preliminarily held in downfolded position and showing in broken lines how the container would appear if set up without first turning back the closure flaps.

The mechanism is designed to be incorporated within ordinary or standard production lines and includes a conveyor to advance containers that have already been filled with bottles or other goods so that the containers are ready to be operated on by machines which will seal the top closure flaps. The containers will have their closure flaps held in outwardly downfolded positions, the flaps being held as in the present instance by short integral connecting strips. The containers are advanced contiguously on constantly moving belts which will slip beneath the containers. They are then fed singly onto a conveyor which propels them past a cutting device at a cutting station to sever one of the connecting strips between a pair of cover flaps. The containers are then delivered without relative change of position to a second conveying device at right angles to the first conveyor and this second conveying device propels the containers past a second cutting device which will sever the connecting strip between the remaining pair of connected cover flaps.

As the containers pass beyond the second cutting device the released cover flaps are engaged by folding plows which engage the flaps and fold them outward and upward ready for the flap sealing operation.

Referring more particularly to the drawings, the device is suitably supported on vertical, longitudinal and transverse frame members indicated at 1, 2 and 3. Journalled on the frame members on supplemental frame elements 4, 4 are shafts 5 and 6 carrying near their ends belt pulleys 7, 7 and 8, 8 over which pass belts 9, 9, spaced apart but sufficiently close to carry the filled containers.

Arranged between belts 9, 9 is a lug chain conveyor, indicated as a whole at 10. In line with the belt conveyor and lug chain conveyor is a transfer conveyor, indicated as a whole at 11, to receive cases which are to be transferred to another lug chain conveyor at right angles to conveyor 10 and indicated as a whole at 12.

The container for which the device is designed, designated as a whole at C, is in the present instance indicated as a so-called regular slotted container made of a onepiece blank and secured at the box factory in collapsed tubular form. The container comprises four interconnected side and end walls 15, 16, 17 and 13 and may be connected in collapsed tubular form, for example, by stapling or taping the walls at the free edge of the blank such as, for example, walls 16 and 17. The cover flaps 19, 20, 21 and 22 are hinged respectively to walls 15, 16, 17 and 18. The cover flaps, as shown in the present instance, are connected with integral sections between flaps 19 and 20, as indicated at 23, and between flaps 21 and 22, as indicated at 24. -By first folding the aligned fiaps 21 and 22 and the aligned flaps 17 and 18 against theirattached walls before expanding the container, the conatiner may then be expanded, as shown in full lines in FIGURE 5. The bottom flaps may then be sealed and the container is ready to receive its contents. Meanwhile the cover fiaps will be held closely against their attached walls. There will, however, be a slight outward flaring of the end corner portions of the cover fiaps which are not connected.

The lug conveyor 10 is arranged to receive filled containers brought forward by the belt conveyors 9, 9. For this purpose the lug conveyor 19 is made narrow enough to fit within the space between the belts. The lug chains 27, 27 carrying spaced lugs 28, 28 pass over front and rear sprockets 29, 30 secured on respective shafts 31 and 32 which are journalled in the frame pieces 4, 4.

Sprockets 33 and 34 are secured on shafts 6 and 32 and over these sprockets passes a chain which passes in turn over a driven sprocket 36 secured on a shaft 37 driven by a motor, not shown, through gearing in gear box 38. As shown in FIGURE 1, the belt rollers are somewhat larger in diameter than the lug chain sprockets, thus causing the belts 9, 9 to travel somewhat faster than the lug chain 10. The lugs 28, as shown, extend somewhat above the level of the belts 9, 9.

The filled containers are designed to accumulate on the belts 9, 9 and the conveyors, not shown, which feed to such belts, and are held just prior to the point of delivery to the lug conveyor 10. For this purpose, as herein shown, a fixed stop element 40 is arranged at the side of one of the belts 9 so as to project a short distance into the path of the leading container and arrest the movement of the entire accumulation of containers. Guide members 41 and 42 are arranged on the opposite side of the belt conveyor to keep the containers moving in a straight line. However, guide member 42 is flared somewhat outwardly away from the belt conveyor to allow the leading end of the container to be moved sufficiently to clear the stop 40.

In order to cause the leading container to clear the stop 40 there is arranged a piston type plunger 43 operated by cylinder 44. The operation of the plunger 43 may be by manual control or may be timed with the movement of the lugs 28 in a manner well known in the art. In normal operation, as soon as a lug 28 has passed around the sprockets 29 on which the chains 27, 27 operate, the plunger 43 will be extended sufficiently to move the leading end of the container over to clear the stop 40. The belts 9, 9 being in motion, will then immediately advance the accumulation of containers. The plunger 43 will then be retracted.

The leading container, just released, will then be brought back into alignment with the belts 9, 9 by a flaring guide end 45 on a guide bar 46 which may be secured on the frame piece -4. The next container following the one just released will normally advance in a straight line and will come into contact with the fixed stop 40, thus again arresting the accumulation of containers.

The purpose of the lug conveyor 10 is to propel the container past a cutting device, such as a fixed cutting blade 48, so that such blade may sever the connecting strip 24 which connects cover flaps 21 and 22. It is desirable therefore that the side wall 17 of the container be caused to move in close contact with the guide rail 46. It is to be understood that this guide rail is low enough to clear the lower edge of the downturned flap 21. This allows the leading edge of the flap 21 to flare out slightly, the extent of the flare depending on the condition of the paperboard.

For the purpose of causing the side wall of the container to move firmly along the guide rail 46 pressure is preferably applied on the opposite side of the container. As herein shown, a springloaded roll 49 is arranged on a bracket 50 and the spring is applied so that the roll 49 bears firmly against the side of the advancing container.

It is desirable to defer the contact of the connecting strip with the knife blade 48 until the propelling lug is in firm contact with the trailing edge of the container and for this purpose a pair of raised or humped strips 51, 51 is arranged adjacent the cutter blade. These strips exert enough retarding force on the container so that the belts 9, 9 are not able to advance the container. Thus the container is held stationary until the lug on the lug conveyor moves up into firm contact with the container.

After the container has been propelled past the blade 48 so that the blade has severed the connecting strip 24 the ug conveyor 10 delivers the container onto the transfer conveyor 11 which is located within the confines of the lug conveyor 12.

Lug conveyor 12 will first be described. As shown in FIGURES 2 and 3 the lug conveyor 12 comprises a pair of sprocket chains 52 and 53 passing over pairs of sprockets 54, 54 and 55, 55 mounted on respective shafts 56 and 57 journalled near the opposite ends of combined frame pieces and guide rails 58 and 59 extending at right angles to frame pieces 4, 4. The lug conveyor carries spaced lugs 60, 60. The shaft 57 has keyed thereon a sprocket 61 over which passes a sprocket chain 62, passing in turn over a driven sprocket 63 on a shaft 64 driven from the gearing in gear box 38.

Within the space between the upper and lower paths of the lugs 60, 60 is a set of driven rolls comprising the transfer conveyor 11. These rolls indicated at 67, 67 are mounted on spindles journalled in extensions of the frame pieces 4, 4 and are frictionally driven by a belt 68 passing over a pulley 69 suitably driven by a motor 70 supported on bracket 71 on one of the vertical main frame members 1. A series of supplemental rollers 72, 72 suitably supported, serve to hold the belt 68 tightly against the surfaces of the rolls to drive them. The result is that as soon as the lug 28 passes around sprocket 30, no longer propelling the container, and also after the container passes beyond the ends of belts 9, 9, the rollers 67, 67 serve to advance the container.

The gearing driving the two lug conveyors 10 and 12 is so adjusted that a container will be delivered from lug conveyor 10 onto the driven rolls 67, 67 before one of the lugs 12 comes into position to propel the container.

The guide rail 59 is suitably secured to the frame so that its upper edge will receive contact by the container wall 16 without contacting the lower edge of the top closure flap 20. The propelling movement of the driven rolls 67, 67 thus forces the container into contact with this guide rail. At a suitable distance along the guide rail is arranged a second severing device also herein shown as a cutting blade indicated at 74. The blade is in close relation to the guide rail 59.

To facilitate entry of the blade between the unattached leading edge of the downturned closure flap 20 the container is caused to be somewhat distorted fom rectangular condition. For this purpose an abutment member 75 in the form of an adjustable screw is threaded into an upstanding bracket 76. The engaging surface of the screw may be adjusted inward or outward as desired with respect to the guide rail 59. The position of the screw is elevated and located so that the screw head will come into contact with the container near the top of the container and approximately at the container corner above the connecting strip 23. This causes the container to be distorted so that the lower corner portion of the downturned cover flap at the other end from the connecting strip 23 will tend to be projected outward away from the side wall 16, thus opening wider the space where the cutting blade is to enter.

As the container is propelled past the cutting blade 74 it is supported on a plurality of antifriction rolls 77, 77 suitably carried on the machine frame.

As the container is beginning to be advanced by a lug 60 off the live rolls 67, 67 and onto the rolls 77, 77, it is desirable to assure that the severed flap 22 on the left side of the container, as viewed in FIGURES 2 and 4, will be caused to swing somewhat outwardly of the container so that it will be readily engaged and swung by the flap plow, described below, located on this side of the container path. For this purpose a preliminary flap swinging device, indicated as a whole at 78, is provided. This device is disposed along the guide rail 58 and is in the form of a spring-loaded bracket 79, swingably mounted, and having a horizontal lower plate with an inclined cam edge 80 to contact laterally against the container wall 18 near its lower edge and guide or urge the container toward the right, as viewed in FIGURES 2 and 4. This'action is assisted by the coil spring 81. The preliminary flap swinging device comprises an upstanding element, herein shown in the form of a blade portion 82, the end of which is designed to slip in between the downturned flap 2-2 and the end wall 18. The forward end of the upstanding blade portion 812 is flared outwardly away from the container, causing the severed flap 22 to swing partially outwardly away from its attached wall 18 and thus assure that the flap 22 will be in proper position to clear and be swung upwardly by the flap plow described below.

At the discharge end of the lug chain 12 is arranged a driven roller 84 mounted on a shaft 85 journalled in the frame and having a sprocket 86 secured on its end. This sprocket is driven by a sprocket chain 87 passing around a similar sprocket 83 secured on the end of shaft 57 opposite the sprocket 61. When the lug 60 passes through the space between the end of rolls 77 and the driven roller 84, the roller 84 will serve to propel the container onto a conveyor, not shown, leading to the machine that will perform subsequent operations on the container.

As the container nears the end of the lug chain 12 it is desirable to swing the released flaps 20 and 22 upward and for this purpose upwardly inclined plow rods 89 and 90 are secured on suitable brackets 91 and 92.. The plOW rods are spaced slightly outward of the adjacent guide rails 58 and so that they will engage beneath the released cover flaps 2d and 22 and swing them upward as the container is propelled past the plow rods.

If desired, the end portions of the plow rods 8-9 and 90 may each be formed in the shape of a helix, whereby the end flaps 2i) and 22 may first be swung upward and then inwardly and downwardly over the contents of the container through an angle of approximately 270 to bring them down low enough over the contents so that the side flaps, after having glue applied thereto, will readily engage on the top surfaces of the downfolded end flaps and fold them completely down so that the side flaps will be secured to the end flaps in the usual manner.

To summarize, the filled containers with downwardly held cover flaps are accumulated on the belt conveyor 9 and are released singly onto the lug conveyor 10. The con tainers are first propelled past the cutting device which severs the connecting strip 24 between cover flaps 21 and 22. The containers move then onto a transfer section 11 and, without being turned, are thereafter moved at right angles past a second cutter device 74 which severs the connection between the cover flaps 19 and 23. After the cover flaps have both been released they are swung outwardly as the container is propelled past the inclined plow rods and then, if desired, may be further swung downwardly over the contents so as to prepare the containers for the subsequent top sealing operation.

While the present description sets forth a preferred form of the invention, numerous changes may be made in the construction as disclosed without departing from the spirit of the invention, and it is therefore desired that the present disclosure be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing descriotion to indicate the scope of the invention.

We claim:

1. A mechanism for severing the holding means between the adjacent edges of the cover flaps of a resilient rectangular container on which the outwardly downturned cover flaps at opposite vertical corners of an expanded container are held along their meeting edges by short connecting strips so that the vertical connected edges of the cover flaps will be forced to remain in close relation to the attached respective container side and end walls, and the opposite, unconnected vertical edges of the flaps will flare somewhat away from their respective attached walls, such mechanism comprising conveying means to advance a container as described with a flaring flap edge in ad vance of the vertical flap edge connected to the edge of its adjacent flap by the connecting strip, and a strip severing device arranged along an edge of the conveying means in the path of the connecting strip, whereby when the connecting strip advances past the severing device, it will be severed to disconnect the vertical edges of the joined flaps.

2. The mechanism as defined in claim 1, including guide means along the conveying means against which guide means the container is arranged to be guided so that its side wall carrying the adjacent downturned flap may bear against such guide means, said severing device being closely related to the guide means, and means for causing the container side wall to bear firmly against the guide means.

3. The mechanism as defined in claim 1, in which the conveying means is in the form of an endless conveyor carrying spaced push bars arranged to bear upon the trailing edge of a container to forcefully move the container past the severing device.

4. A mechanism for severing the holding means between the adjacent edges of cover flaps of a resilient, rectangular container on which the outwardly, downturned cover flaps at opposite vertical corners of an expanded container are held along their meeting edges by short connecting strips so that the vertical connected edges of the cover flaps will be forced to remain in close relation to the attached respective container side and end walls, and the opposite unconnected vertical edges of the flaps will flare somewhat away from their respective at tached walls, such mechanism comprising two laterally spaced belt conveyors which may slip beneath the container but which will advance a container as described with a flaring flap edge in advance of the vertical flap edge connected to the edge of its adjacent flap by the connecting strip, a strip severing device arranged along an edge of one of the spaced belt conveyors and in the path of the connecting strip, whereby, when the connecting strip advances past the severing device, it will be severed to disconnect the vertical edges of the joined flaps, the spaced belts having arranged between them a constantly driven endless conveyor carrying spaced push bars to bear upon the trailing edge of a container to forcefully advance it past the severing device, and releaseable stop means associated with the spaced belt conveyors and arranged ahead of the severing device to arrest the container against movement by friction of the endless belt conveyors until a push bar has contacted against the trailing edge of the container held by the releasable stop means and forced it past such stop means.

a 5. A mechanism for severing the holding means between the adjacent edges of cover flaps of a resilient rectangular container on which the outwardly downturned flaps at opposite vertical corners of an expanded container are held along their meeting edges by short connecting strips so that the vertical connected edges of the cover flaps will be forced to remain in close relation to the attached respective container side walls and end walls, and the opposite unconnected vertical edges of the flaps will tend to flare somewhat away from their respective attached walls, such mechanism comprising a first conveying means for advancing the container past a first cutting station where the connecting strip between two joined cover flaps is severed, a second conveying means aligned with the first conveying means for receiving the container after the first connecting strip has been cut, a third conveying means disposed at approximately right angles to the first and second conveying means for propelling the container at right angles to its first direction of travel without changing its relative position, combined stop and guide means on the side opposite the first and second conveying means for first stopping the container in alignment with the third conveying means and thereafter guiding it in such alignment, a strip severing device in close relation to the guide means for the third conveyor, and means for holding the container firmly against such guide means as the strip severing device severs the strip joining the second pair of connected cover flaps and as the container is propelled past such severing device.

6. A mechanism as defined in claim 5 in which the first conveying means includes an endless conveyor with spaced push bars for propelling cases past the first strip severing station and the third conveying means comprises an endless conveyor also provided with spaced push bars and operating in a direction at right angles to the first push bar conveyor, means for driving both push bar conveyors in synchronism, whereby a container will be delivered to the second push bar conveyor ahead of an oncoming push bar on said second push bar conveyor.

7. A mechanism as defined in claim 6 in which the second push bar conveyor comprises endless sprocket chains or the equivalent passing over sprockets at each end thereof, the sprocket chains being spaced apart to include between them the second conveying means aligned with the first conveying means for receiving the container after the first connecting strip has been cut, such second conveying means comprising a set of rollers the top surfaces of which are disposed laterally between the sprocket chains and below the push bars on the push bar conveyor, means for driving the rollers to advance the container toward the stop and guide means, said rollers being adapted to support and convey the container into position ahead of an advancing push bar on the second push bar conveyor and to move the container firmly against the combined stop and guide means.

8. In a mechanism for severing the holding means between the adjacent edges of cover fiaps of a resilient rectangular container on which the outwardly downturned flaps at opposite vertical corners of an expanded container are held along their meeting edges by short connecting strips so that the vertical connected edges of the cover fiaps will be forced to remain in close relation to the attached respective side and end walls, and the opposite unconnected vertical edges of the flaps will tend to flare somewhat away from their respective attached walls, the combination of a first conveyor for propelling the container along a fixed path, a first cutting station operatively associated with the first conveyor at which one of the connecting strips is cut, a second conveyor arranged at right angles to the path of the first conveyor to receive a container from the first conveyor, and means on the second conveyor to propel a container therealong without changing its relative position, guide means along the second conveyor on the side opposite the first conveyor, a second severing device closely related to such guide means, said second severing device being arranged to sever the strip between the second pair of connected flaps as the container is propelled past such severing device, and means for firmly holding the side of the container against the guide means while the uncut strip holding the connected flaps is being severed.

9. Mechanism as defined in claim 8 comprising an upwardly inclined plow rod on the side of the second conveyor and located downstream from the severing device and approximately in line with the guide means for engaging the unattached edge portion of the freshly detached cover flap and swinging such fiap outwardly and upwardly as the container is advanced.

10. Mechanism as defined in claim 8 comprising an upwardly inclined plow rod on the side of the second conveyor adjacent the first conveyor, a flap spreader device located on the same side of the second conveyor with the plow rod and substantially aligned therewith, said flap spreader device including a cam surface inclined forwardly and inwardly in the direction of travel to contact the adjacent container wall below the lower edge of the attached downturned cover flap and force the container laterally in the direction of the second severing device, and means on the flap spreader device for engaging and spreading the leading edge portion of the first severed flap away from its wall, whereby the leading edge of the flap will pass in the clear outside the plow rod and thereby be swung outwardly as the container is advanced.

11. In a mechanism for severing the holding means between the adjacent edges of cover flaps of a resilient rectangular container on which the outwardly downturned flaps at opposite vertical corners of an expanded container are held along their meeting edges by short connecting strips so that the vertical connected edges of the cover flaps will be forced to remain in close relation to the attached respective side and end walls, and the opposite unconnected vertical edges of the flaps will tend to flare somewhat away from their respective attached walls, the combination of a first conveyor for propelling the container along a fixed path, a first cutting device operatively associated at one side of the first conveyor at which the first connecting strip is cut, a second conveyor arranged at right angles to the path of the first conveyor and arranged to receive a container from the first conveyor and means on the second conveyor to propel the container therealong without changing its relative position, a first guide means along the first conveyor on the side opposite to the first cutting device, said first guide means being arranged at a level above the first and second conveyor and terminating at the side of the second conveyor which is opposite the first conveyor, a low guide bar along the second conveyor extending a short distance above the level of the second conveyor, a cutting blade disposed in substantial alignment with the low guide bar in position to be interposed between the unconnected portion of the secured cover flap and its attached side wall, an abutment member supported at the approximate level of the first guide means and against which abutment member the secured end of the strip connected flap will impinge when propelled thereagainst by the first conveyor, whereby the container will be distorted from a rectangular condition, causing the unconnected leading edge of the fiap adjacent the low guide bar to flare outwardly to clear the cutting blade to give the blade free access to the connecting strip when the conveyor propels the container to bring the strip into contact with the blade.

12. In a mechanism for severing the holding means between the adjacent edges of cover flaps of a resilient container of rectangular form on which the outwardly downturned flaps at opposite vertical corners of an expanded container are held along their meeting edges by short connecting strips so that the vertical connected edges of the cover flaps will be forced to remain in close relation to the attached respective side and end walls, the opposite vertical edges of the flaps being unconnected to the edges of the adjacent cover flaps at the remaining two vertical corners, the combination of a first conveyor for propelling the container along a fixed path, a first cutting station operatively associated with the first conveyor at which one of the connecting strips is cut, a second conveyor arranged at right angles to the path of the first conveyor to receive a container from the first conveyor, and means on the second conveyor to propel a container therealong without changing its relative position, guide means along the second conveyor on the side opposite the first conveyor, a second severing device closely related to such guide means, said second severing device being arranged to sever the strip between the second pair of connected flaps as the container is propelled past such severing device, an upwardly inclined plow rod on the side of the second conveyor adjacent the first conveyor and adapted to engage and swing the first severed flap upwardly as the container advances, a preliminary flap spreader device located on the same side of the second conveyor with the plow rod and substantially aligned therewith, said flap spreader device including a vertically positioned element disposed in close relation to the path of the outside surface of the adjacent container wall for engaging and spreading outwardly the leading portion of the first severed flap away from its attached wall, whereby the leading edge of the flap will pass in the clear outside the plow rod and thereby be swung outwardly as the container is advanced.

13. Mechanism as defined in claim 1, including plow means disposed along the side of the conveying means, 10-

cated downstream from and approximately in line with the severing device for engaging the unattached edge portion of the freshly detached cover flap to swing such flap outwardly and upwardly as the container is advanced.

14. Mechanism for severing the holding means between the adjacent edges of cover flaps hinged to the upright walls of a resilient, rectangular container on which the outwardly downturned cover flaps at opposite vertical corners of an expanded container are held along their meeting edges by narrow strips so that the vertical connected edges of the flaps will be caused to remain in close relation to the attached respective container Walls, and the opposite unconnected vertical edges of the flaps will flare somewhat away from their attached walls, such mechanism comprising a flap severing station, conveying means to advance a container as described past such flap severing station at which the connecting strip may be severed between two adjoining flaps at one corner of the container to free such flaps to swing to their closed positions, a second flap severing station and conveying means for advancing such container past the second station in a position in which a flaring, vertical flap edge of one of the two remaining connected flaps will be disposed in advance of the edge which is connected to the adjoining flap by the connecting strip, a strip severing device located along the side of the conveying means and in the path of the connecting strip, whereby, as the container advances past the severing device, the connecting strip will be severed to disconnect such flaps so that they may be swung to closed position, and plow means disposed on each side of the container path and located downstream from the second flap severing station, said plow means being engageable with the respective opposite released flaps carried on hinge lines extending parallel with the line of travel to swing such flaps outwardly and upwardly as the container advances.

15. A mechanism as defined in claim 1, in which the conveying means for the container comprises a pair of spaced, endless members supporting a push lug for propelling the container, guide means for the container arranged along one side of the conveying means, said severing device being closely related to the guide means, a group of live rolls disposed between the spaced, endless members, but out of the path of the push lug, for supporting the container, the live rolls being arranged with their axes located lengthwise of the endless members, and the rolls being rotatable to urge the container against the guide means.

References Cited UNITED STATES PATENTS 3/1949 Ross 53-208 1/1962 Eichorn 53208 

